Johannes Spille

Purpose: Dental implant placement is a technically demanding procedure in which surgical experience is considered a key determinant of outcome. Primary stability, as measured by the implant stability quotient (ISQ) via resonance frequency analysis (RFA), is a critical predictor of successful osseointegration. This study aimed to quantify the influence of surgical experience on primary implant stability in a standardized porcine mandible model. Methods: Dental students with no prior implant experience and experienced oral surgeons placed implants using two commercially available systems (Straumann Standard Plus and Astra Tech EV). Primary stability was assessed by RFA immediately after insertion at four standardized measurement positions. ISQ values were analyzed using a linear mixed-effects model with surgical experience, implant system, and measurement position as fixed factors and a random intercept for implant to account for the non-independence of the four measurements obtained per implant. Results: A total of 760 ISQ measurements were included in the analysis. Experienced surgeons achieved significantly higher ISQ values (M = 75.72, SD = 5.22) than students (M = 68.68, SD = 11.61; p < 0.001), with an overall mean difference of approximately 7 ISQ points. Within the Straumann Standard Plus, the difference was 8.14 ISQ points ( p = 0.028); within the Astra Tech EV, the difference was 5.42 ISQ points ( p < 0.001). Variability was markedly greater in the student group across both systems. Conclusions: Surgical experience significantly influences primary implant stability within both implant systems investigated. Novice operators achieve lower and less consistent ISQ values, which may have clinical implications for the selection of loading protocols. These findings suggest that structured training may help improve primary stability among less-experienced operators, a hypothesis that warrants prospective clinical evaluation. Clinical trial number: Not applicable.

Background: Surgical management of malignant tumors in the orofacial region frequently necessitates extensive resection, resulting in significant functional and aesthetic morbidity. In younger patients, these sequelae carry a substantial psychosocial burden, emphasizing the need for minimally invasive reconstructive strategies that preserve quality of life while maintaining oncological safety. Case presentation: A 36-year-old female patient presented with a small 1 × 1 cm swelling at the junction of the hard and soft palate on the left side. Incisional biopsy confirmed a malignant minor salivary gland tumor but did not permit definitive subtyping. The final diagnosis of a polymorphous adenocarcinoma (PAC), conventional subtype, was established only on the complete resection specimen. Following oncologically adequate resection, including partial hard palate and tuberosity removal, a 3 × 4 cm defect was reconstructed with a free upper arm flap. Supermicrovascular anastomoses to the superior labial and facial arteries (vessel diameter ~ 0.2 mm) were performed via a transoral approach using the Symani ^® robotic surgical system with 20× motion scaling. Venous anastomoses to the facial vein were completed end-to-end and end-to-side via the same intraoral access. Selective lymph node sampling of the four radiologically prominent ipsilateral level II lymph nodes through a minimal cervical incision showed no metastases, both on frozen section and on final histopathology (0/4). Final histopathology demonstrated a 15 mm low-grade PAC resected in sano, without lymphovascular invasion, without unequivocal perineural infiltration and without bone invasion, classified as pT1 pN0 (0/4) cM0, R0. Postoperative course was uneventful; functional rehabilitation including speech and swallowing therapy is ongoing. Conclusions: Robotic-assisted supermicrosurgery using the Symani ^® system enabled safe transoral free flap reconstruction of a posterior palatal defect with anastomoses at the sub 0.2 mm scale. This approach minimizes donor-site morbidity and demonstrates the feasibility of intraoral robotic supermicrosurgery as a novel reconstructive modality in head and neck oncology.

Purpose: Despite the growing clinical application of diode lasers in oral surgery, laser training remains underrepresented in dental curricula. This study evaluated the feasibility of structured preclinical diode-laser training and characterized the early learning curve of undergraduate dental students without prior laser experience, using target-based accuracy of laser incisions compared with a familiar scalpel reference condition. Methods: 22 dental students performed standardized linear incisions on porcine skin at three time points. Each session comprised five incisions (target: 10 mm length, 2 mm depth, minimal width): four diode-laser settings (1 W/pulsed, 3 W/pulsed, 1 W/continuous, 3 W/continuous; 445 nm wavelength; 320 μm fiber) and one scalpel incision. Incision morphology was assessed by micro-computed tomography. Operative time was recorded per incision, and subjective workload was evaluated using the NASA-TLX questionnaire. Results: Total operative time decreased significantly across sessions (p = 0.006). Per-method reductions were significant only for the two pulsed settings. Four of six NASA-TLX subscales improved (all p ≤ 0.013). Length accuracy improved significantly over time (main effect of time p < 0.001) with no method-time interaction and comparable, significant within-method gains for all methods. Depth accuracy showed only a small overall time effect and a significant within-method gain for a single laser setting (1 W pulsed). Incision width did not change significantly over sessions for any method. Laser incisions were consistently wider than scalpel incisions. Conclusion: Structured preclinical laser training on porcine skin is feasible and is associated with early gains in operative efficiency, perceived workload and length accuracy. These gains largely reflect general task familiarisation rather than a laser-specific learning advantage. The findings support integrating structured laser training using animal-tissue models into dental education but cannot establish clinical competence, equivalence to scalpel surgery, or transfer to intraoral patient care.

Purpose: To evaluate the learning curve and accuracy of microsurgical operation steps achieved by young medical professionals using a microsurgery robotic simulator. The NASA-TLX score was used to assess the workload in the simulation of robotic operation steps for surgical beginners. Methods: Twenty-three students of dental medicine performed four exercises over 3 consecutive weeks. The exercises consisted of grasping and placing models, grasping and placing a needle, and performing a surgical knot. Results: There was significant improvement ( p < 0.05) in the operation time from the first to the second and third measurement points for all exercises. Furthermore, the range of instrument movement became more efficient as the learning curve progressed. The incidence of complications such as instrument collisions improved with each trial. The workload was reduced significantly by the training sessions. Conclusion: Our study showed that the young medical professionals had a significant learning curve on a microsurgery robotic simulator. The simulator provided a suitable opportunity for students and young professionals to prepare for robotic microsurgery and pique their interest in the field.

Background/Objectives: In oral and maxillofacial surgery, apicoectomy is a standard procedure for treating persistent periapical infections after insufficient conservative treatment. Traditional techniques rely on direct visualization, while navigated methods offer advantages in precision and safety. This in vitro study compared conventional apicoectomy with dynamically guided navigation. The aim was to assess the feasibility, accuracy, and safety of dynamic navigation and to determine whether it reduces complication risks, improves surgical predictability, and minimizes bone loss. Methods: Ten experienced surgeons performed both techniques on custom-designed models. Operation time was assessed, as well as cavity volume, resected root length, incision width and height, and preservation of adjacent structures. Results: The navigated approach demonstrated significantly improved accuracy in root-end resection, with a reduction in access cavity volume (p < 0.001). No significant differences were found in operation time (p = 0.499), resection length (p = 0.054), or incision dimensions (p > 0.05). The risk of damaging adjacent structures was not significantly different between the two methods. Conclusions: Dynamic navigation for apicoectomy can offer an alternative in cases requiring high precision to conventional techniques. However, the routine clinical implementation of dynamic navigation remains limited due to the extensive preoperative planning required. The necessity for additional planning increases complexity, time, and cost.

Background/Objectives In oral and maxillofacial surgery, apicoectomy is a standard procedure for treating persistent periapical infections after insufficient conservative tre-atment. Traditional techniques rely on direct visualization, while navigated methods offer adventages in precision and safety. This in vitro study compared conventional apicoec-tomy with dynamically guided navigation. The aim was to assess the feasibility, accuracy, and safety of dynamic navigation and to determine whether it reduces complication risks, improves surgical predictability, and minimizes bone loss. Methods Ten experienced surgeons performed both techniques on custom-designed models. Operation time was assessed, as well as cavity volume, resected root length, incision width and height, and preservation of adjacent structures. Results The navigated approach demonstrated sig-nificantly improved accuracy in root-end resection, with a reduction in access cavity volume (p < 0.001) and a more precise resection length (p = 0.049). No significant dif-ferences were found in operation time (p = 0.499) or incision dimensions (p > 0.05). The risk of damaging adjacent structures was not significantly different between the two methods. Conclusions Dynamic navigation for apicoectomy can offer an alternative in cases re-quiring high precision to conventional techniques. However, the routine clinical im-plementation of dynamic navigation remains limited due to the extensive preoperative planning required. The necessity for additional planning increases complexity, time and cost.

The aim of the current study was to compare the accuracy of objectively graded microsurgery steps by young professionals using a microscope and a microsurgery robot. 40 students performed three exercises with a dental surgical operating microscope and a microsurgery robot. The exercises consisted of grasping and placing a needle, threading the needle, and performing a surgical knot. All students successfully completed the exercises with the microscope and the Symani. The microscope demonstrated significantly shorter operating times for grasping and placing a needle ( p = 0.003) and for a single-button suture of an anastomosis ( p < 0.001). Gaming, sewing, or knitting had a significant advantage for both the microscope and the Symani for grasping and placing a needle ( p < 0.001). Young professionals appear to be able to work adequately with both the microscope and the robot in the surgical model for anastomoses. The students demonstrated a strong interest in adopting robotic technologies, which is why implementing robotics in the clinics' teaching process is necessary. This could inspire the next generation of medical professionals for robotic surgery and microsurgery, as well as support their career path.